Screed unit



p 12, I A. s. MILLIKIN ETAL 2,358,085

SCREED UNIT Filed Oct. 2, 1942 I INVENTOR S Arnold S. Millikm.

John H. Apel.

TJRNEYS Patented Sept. 12, 1944 SCREED UNIT Arnold s. Mlillikin and John H. ApeL Columbus Ohio, assignors to The Jaeger Machine Com pany, Columbus, Ohio, a corporation of Ohio Application October 2, 1942, Serial No. 460,482

16 Claims.

Our invention relates to a screed unit. It has to do, more particularly, with a screed unit for road finishing machines which will effectively finish the surface of a layer of plastic material,

such as concrete or asphalt, and will impart the desired crown thereto.

One of the objects of our invention is to provide a screed unit which has a finishing surface that may be effectively adjusted by simple means so that it will produce accurately any desired and predetermined crown on the surface being finished.

Another object of our invention is to provide a screed unit of the type indicated wherein the crowning means for the surfacing member serves, to curve such member the same at its front and rear edges so as to produce a symmetrical curve. Another object of our invention is to provide a screed unit which has means associated with the finishing surface for tilting it transversely of itself so that its forward and rear edges will be at different levels in order to obtain a troweling action on the material being finished.

Another object of our invention is to provide a screed unit which is of such a nature that it will function both during forward movement of the machine on which it is, mounted and rearward movement of the machine.

Another object of our invention is to provide a screed unit which is of very simpleconstruction but which will readily withstand all the shocks and stresses to which it is subjected.

In its preferred form, our invention contemplates the provision of a screed unit which is up against it during the rearward'movement of the machine. The forward and rearward plates not only serve to contact the material, as indicated, but alsoserveto support the bottom finishing orsurfacing plate. The surfacing plate extends longitudinally of the front and rear plates and is disposed therebetween at the lower 4 edges thereof.

The surfacing plate is suspended from the front and. rear plates by means of a plurality of independently adjustable suspending members. ::These suspending members may be initially adz-ju'sted to position the-surfacing member relative thereto.

to the front and rear plates as desired. For example, they may be adjusted tomove the surfacing plate vertically relative to the other plates, to tilt it transversely, or to curve it longitudinally. I

This application is a continuation-in-part'of our co-pending application Serial No. 348,376, filed July 30, 1940, now Patent 'No. 2 ,299,700', issued October 20,1942 7 a I The preferred embodiment ofour invention is illustrated in the accompanying drawing wherein similar characters of reference designate corresponding parts and wherein:

'Figure 1 is a perspective view illustrating a surfacing machine having a screed unit, constructed according to our invention, applied Figure 2 isra view of the screed unit', partly in longitudinal section and p-artlyin front elevation, and illustrating the means forchanging I the crown of the surfacing member.

. screed unit. 7

Figure 3 is a planviewof a-portion of the Figure 4 is a transverse vertical sectional View taken substantially alongline 4 -4 of Figure 2. Figure 5 is a transverse sectional view similar to Figure 4 but showing-how the surfacing member may be tilted transversely, 7

Figure 6 is a perspective View, partly broken away,.of the screed unit illustrated in Figure 1.

With reference to the drawing, we have illustratedin Figure 1 a finishing machine which may be designated. generally by the numeral I, and which is supported by wheels 2" for operation upon said forms 3. A screed unit, which may be indicated generally by the number 4, is supported at the front of thefinishing machine by roller-type supportingunits do in such a manner that it may be reciprocated transversely of the path of movement of the. machine. The screed unit is adapted to be reciprocated by ,means of the mechanismJindi-cated by the numeral 5.

The structure of the screed .unit v4, 'shown 'in Figure 1, is. clearly illustrated in Figures'2- 1to*6,

inclusive. The screed unit'is preferablyflconstructed in the form of a box, girder: or beam;

It comprises a vertically disposed front plate16 and a vertically disposed rearplate I which extend the full length of the screed unit and which are disposed in spaced relationship, Dis posed between the platesii and 1, at the lower edges, thereof, is the surfacing plate -8 which extends substantially the full lengthof the plates 6 and 1. This plate 8 is flexibleand is provided plates 6 and I. tical movement of plate 8 relative to plates 6 and with a short upturned flange 9 (Figure 4) at its forward edge and a short upturned flange H) at its rear edge. In bending these flanges 9 and I0, curved corners 9a and "la are produced which act more effectively on the material than sharp corners.

The lower edge of the plate 6 is bent inwardly as at llto a slight extent and the lower edge of the plate I is similarly bent as at [2. The portions II and I2 will always overlap the flanges 9 and Ill. The upper edge of each of the plates 6 and 1 is turned inwardly and then downwardly as indicated at l3 for reinforcement of the plates. The plates 6 and I are secured together at their upper edges by means of a pluralityof bars M which are spaced longitudinally thereof and which extend transversely thereof. These bars l4 are suitably bolted by means of bolts l5 to the upper edges of the platest and 1. Cover plates 16 may also be provided for the full length of the plates 6 and 1. These plates [6 fit between the bars l4 and are provided with resilient flanges Ilia which snap down over the plates 6 and I and "hold the plates IS in position. Each end of the screed unit is preferably closed by means of a plate I! which is suitably secured tothe ends of the plates 6 and 1,

Each end of the plate 8 is provided with a section l8 of wear-resisting steel which is adapted to rest on the adjacent form 3. This section is extended forwardly beyond forward plate 6 and is provided at its forward and inner edge with a vertically disposed end shoe l8a which prevents the material from being spread beyond the end jof the screed unit. The section I8 is preferably bolted to the plate 8 as shown at [8b in Figure 2. The surfacing plate 8 carries the transversely extending longitudinally spaced shoes 23. Each of these shoes has a pair of bolts 24 pivoted thereto as at 25. The upper end of each of these bolts is threaded as at 24a and receives an internally -threaded nut member 30. Thi nut memberhas integrally formed therewith a lower flanged collar This will produce vertical movement of the bolts 24. A pushing or pulling force will be exerted by rods 24 on plate 8, depending'upon the direction of rotation of nuts 30. In order to prevent longitudinal movement of 'plate 8 relative to plate 6 and I, th plate 8 is i provided, substantially midway between its ends,

with an upstanding transversely extending guide member 3| (Figure 2) bolted to the plate 8. This member 3| extends into a guideway formed by a pair of transversely extending vertically disposed angles 32 which are bolted tothe front and rear This structure will permit ver- 8 may be tilted transversely by proper adjustment of the bolts, as indicated by the dotted lines in Figure 5, in order to obtain a trowelJing action.

Thus, it will be apparent that the screed unit is in the form of a box girder or beam which may be made of less material than prior art screeds. It will still have adequate strength to resist the strains and stresses to which-it will be subjected,

during use. During forward movement of the machine, the front plate 6 will contact with the material which piles up in front thereof. During rearward movement of the machine, the rear plate I will similarly contact the material. Thus, the plates 6 and I serve both as material-contacting plates and as a supporting means for the surfacing plate 8, which is suspended therefrom, and no additional supporting beams are necessary as with prior art structures.

. The member 8 may be adjusted into flat, convex or concave positions by bolts 24. Furthermore, it may be tilted transversely. Due to the fact that a row of members 24 is provided adjacent the front edge of plate 6 and a row is provided adjacent the rear edge of the plate, a symmetrical crown can be, obtained. Furthermore, the member 8 can be tilted transversely and still the desired crown can be obtained.

The screed is more simple in structure and cheaper to manufacture than prior art screeds because the plates 6 and I serve as the supports for plate 8. The screed will be completely closed and, therefore, easier to keep clean.

'Various other advantages will be apparent from the preceding description, the drawing and the following claims.

Having thus described our invention, what we claim is:

l. A screed unit substantially in the form of a box girder comprising. a forward vertically disposed plate and a rear vertically disposed plate which extend longitudinally and are disposed in spaced relationship, a transversely extending means at the upper edges of said forward and rear plates for securing them to each other in spaced relationship, a surfacing plate disposed between the lower edges of said forward and rear plates, said surfacing plate bein flexible, a plurality of rod members for suspending said surfacing plate from said forward and rear plates, said rod members being arranged in two rows adjacent the forward and rear edges of said surfacing plate and being disposed at intervals spaced longitudinally of said surfacing plate, said rod members having their lower ends connected to said surfacing plate and their upper ends connected to said transversely extending mean which secures said forward and said rear plates together, said rod members being independently adjustable to vary the effective length thereof, said surfacing plate having a section at each end which extends forwardly beyond the forward plate, said section earring a vertically disposed shoe which limits spreading of the material beyond the end of said forward vertically disposed plate, said forward and "rear vertically disposed plates being load- 3 carrying members.

2. A screed unit substantially in the form of a box girder comprisin a forward vertically disposed plate and a rear vertically disposed plate which extend longitudinally and are disposed in spaced relationship, means at the upper edges of said plates for securing them to each other in spaced relationship, a surfacing plate, disposed'between the lower ed es .of said forward and rear plates, said surfacing plate being flexible, a plurality of rod members for suspending said surfacing plate from said forward and rear plates, said rod members being arranged in two rows adjacent the forward and rear edges of said surfacing plate and being disposed at'intervals spaced longitudinally of said surfacing plate, said rod members having their lower ends connected to said surfacing plate and their a transversely extending upper end connected to said transversely extending means which secures said forward and said rear plates together, said rod members being independently adjustable to vary the effective length thereof, said forward and rear vertically disposed plates being load-carrying members.

3. A screed unit according to claim 2 wherein the rod members are pivoted at their lower ends to the upper side of said surfacing member to permit relative pivoal movement in a plane transverse of said surfacing member.

4. A screed unit according to claim 2 wherein the surfacing member has upwardly extending flanges at its forward and rear edges which extend into overlapping relationship to said forward and rear plates.

5. A screed unit according to claim 2 wherein said surfacing plate and said forward and rear plates carry vertically disposed cooperating guide members which permit relative vertical movement thereof but prevent relative longitudinal movement thereof.

6. A screed unit according to claim 2 wherein the upper edges of said forward and rear plates are bent into channel form for reinforcement.

7. A screed unit substantially in the form of a box girder comprising a forward vertically disposed plate and a rear vertically disposed plate which extend longitudinally and are disposed in spaced relationship, a transversely extending means at the upper edges of said plates for securing them to each other in' spaced relationship, said transversely extending means comprising split bars having notched portions, a surfacing plate disposed between the lower edges of said forward and rear plates, said surfacing plate being flexible, a plurality of rod members for suspending said surfacing plate from said forward and rear plates, said rod members being pivoted at their lower ends to said surfacing plate for transverse swinging movement and being arranged in two rows adjacent the forward and rear edges of said surfacing plate, said rod members being disposed at intervals spaced longitudinally of said surfacing plate and having upper ends which are threaded, and internally threaded nuts for receiving said threaded upper ends of said rods, saidnuts being embraced by the notched portions of said split bars and having upper and lower flanges engaging said split bars.

8. A screed unit substantially in the form of a box girder comprising a forward vertically disposed-plate and a rear vertically disposed plate which extend longitudinally and are disposed in spaced relationship, a transversely extending means at the upper edges of said plates for securing them to each other in spaced relationship, a surfacing plate disposed between the lower edges of said forward and rear plates, said surfacing plate bein flexible, a plurality of rod members for suspendingsaid surfacing plate from said forward and rear plates, said rod members being arranged in two rows adjacent the forward and rear edges of said surfacing plate and being disposed at intervals spaced longitudinally of said surfacing plate, said rod members having their lower ends connected to said surfacing plate and their upper ends connected to said transversely extending means which secures said forward and rear plates together, said rod members being independently adjustable to vary the effective length thereof, said surfacing member having upwardly extending flanges at itsforward and rear edges joined thereto by curved corners, said flanges extending into overlapping relationship to said forward and rear plates, said forward and rearplates having slightly in-turned lower edge portions for cooperating with said flanges.

9. A screed unit according to claim 7 wherein the upper edges of said forward and rear plates are bent into channel form for reinforcement.

10. A screed unit according to claim '7 wherein the surfacing member has upwardly extending flanges at its forward and rear edges joined thereto by curved corners, said flanges extending into overlapping relationship to said forward and rear plates, said forward and rear plates havin slightly in-turned lower edge portions for cooperating with said flanges.

11. A screed unit according to claim '7 wherein said surfacing member and said forward and rear plates carry vertically disposed cooperating guide members which permit relative vertical movement thereof but prevent relative longitudinal movement thereof.

12. A screed unit according to claim 7 wherein said surfacing member has a section at each end which extends forwardly beyond the forward plate, said section carrying a vertically disposed shoe which limits spreading of the material beyond the end'of said forward vertically disposed plate.

13. A screed unit according to claim 8 wherein the upper edges of said forward and rear plates are bent into channel form for reinforcement.

14. A screedunit according to claim 8 wherein said surfacing member and said forward and rear plates carry vertically disposed cooperating guide members which permit relative vertical movement thereof but prevent relative longitudinal movement thereof.

1 15; A screed unit according to claim 8 wherein said surfacin member has a section at each end which extend forwardly beyond the forward plate, said section carrying a vertically disposed shoe which limits spreading of the material beyond the end of said forward vertically disposed 1 plate.

16. A screed unit substantially in the form of a box girder comprising a forward vertically disposed longitudinally extending plate adapted to contact material'and a rear vertically disposed longitudinally extending plate adapted to contact material disposed in spaced relationship, a longitudinally extending substantially horizontally disposed surfacing plate disposed between the lower edges of said forward and rear plates and separate therefrom, and means for supporting said surfacing plate from said forward and rear plates for adjustable vertical movement relative thereto, said forward and rear plates being load-carrying members.

. ARNOLD S. MILLIKIN.

JOHN H. APEL. 

